Field
The disclosed and claimed concept relates generally to electrical interruption equipment and, more particularly, to a testing apparatus that is usable to test a circuit interruption apparatus.
Related Art
Numerous types of circuit interruption devices are known in the relevant art and are used to interrupt current in a protected portion of a circuit in certain predefined overcurrent conditions, under-voltage conditions, and other conditions. Circuit interruption devices that are intended to be resettable after opening a protected portion of a circuit typically include a set of separable electrical contacts which, when moved from a position in contact with one another to a position spaced apart from one another, cause the protected portion of the circuit to be moved from the closed condition to the open condition. In certain applications, the set of separable contacts may be situated within a vacuum bottle to facilitate arc extinction between the set of separable contacts. It is likewise known in the relevant art, however, that the energy that is dissipated in extinguishing an arc can eventually result in wear on the separable contacts, the vacuum bottle, and on other parts of the circuit interruption device. Moreover, other environmental and other conditions can affect the set of separable contacts, the vacuum bottle, and the other portions of the circuit interruption device.
It thus is desirable to periodically perform a testing operation on a circuit interruption device if it has been in service for a period of time. Such testing might involve a primary resistance test wherein the resistance across the set of separable contacts in the closed position is measured by applying a high level current across the contacts and measuring the voltage drop, or alternatively this potentially can be done by applying an ohmmeter across the closed contacts. Other testing can include a vacuum integrity test wherein a high voltage is applied across the contacts in their open position, and the current flow across the open contacts is measured with the use of an ammeter.
Similar high voltages are applied during insulation integrity testing. Some circuit interruption apparatuses can include accessory devices such as charging motors, under-voltage relays, trip coils, closing coils, and the like, and it may also be desirable to test one or more of the included accessory devices.
Such testing has previously involved a meaningful degree of danger since a circuit interruption device must be removed from, say, the protective environment of its switchgear cabinet and must then have its line and load conductors connected with various electrical cables that are connected with various electrical supplies that are outside the protective environment of the switchgear. Such application of high voltage and/or high current to the exposed circuit interruption device is problematic because electrical cables and conductors are exposed, sometimes lying on the floor, and can create hazards in a busy industrial environment. Moreover, the high current involved with vacuum integrity testing generates X-rays which are themselves hazardous in anything other than minimal amounts. Improvements thus would be desirable.